In general, as illustrated in FIG. 1, a membrane electrode assembly (MEA) 1 of a fuel cell, which is used in a hydrogen fuel cell automobile, is composed of two electrodes (anode and cathode) 1 and 1′ and an electrolyte membrane 2 interposed between the electrodes 1 and 1′, and the membrane electrode assembly (MEA) is referred to as a membrane electrode assembly having a three-layer structure.
When a gas diffusion layer (‘GDL’) (not illustrated) is conjugated onto the electrodes 1 and 1′ of the membrane electrode assembly as described above, a membrane electrode assembly having a five-layer structure is produced.
Here, the electrodes 1 and 1′ are composed of a metal catalyst which generates electrons and a support which supports the metal catalyst and moves electrons. Carbon may be used as a material for the support.
In this case, in order to manufacture the electrodes 1 and 1′, a slurry for a fuel cell is made by using carbon which is a support, a metal catalyst which generates electrons, and a binder (an ionomer) to mix the components with each other.
FIG. 2 illustrates a slurry for a fuel cell in the related art, and the slurry for a fuel cell in the related art is in a state where metal catalysts 3 supported on the carbon support are surrounded by a binder 4 by means of the mixing.
However, as illustrated in FIG. 2, a region V in which the binder 4 is not present around the metal catalyst 3 occurs, which causes an increase in resistance against the transfer of electrons of the metal catalyst 3, and as a result, there may be a problem in that the efficiency of the electrode is reduced.
As the binders 4 included in the slurry prepared as described above flow, a change in viscosity of the slurry occurs, and there is a concern in that the change in viscosity of the slurry may act as a factor which may degrade the dispersibility and stability of the slurry.